Wilfred w



Sept. 6, 1932. W W LOWTH-ER I 1,875,471

AIR' CLEANER Filed July 2o, 1931 entirety by B.

Patented Sept. 6, 1932 UNITED STATES PATENT oFFicE WILFRED W. LOWTHER, OF MINNEAPOLIS, MDNESOTA, ASSIGNOR T COMPANY, INC., OF ST. PAUL, MINNESOTA, A CORPORATION 0F MINNESOTA V AmcLnANEa f,

My present invention relates to .improvements in air cleaners of the general character wherein a body of Huid, usually oil, is employed for accomplishing separation of air from dust and is here illustrated as being incorporated in an air cleaner of .that type disclosed in my co-pending application, Serial No. 551,883, filed of even date herewith,'an d entitled Air cleaner. This type of air cleaners is especially adapted and is generally used in connectionV with internal combustion engines.

'Generally stated, the invention consists of the novel devices, combinations of 'devices and arrangement of parts hereinafter described and defined -in the claims.

The single view of the drawing is a vertical axial sect-ion through one of the improved air cleaners and an4 auxiliary air cleaner used in conjunction therewith.

The air cleaner incorporating the invention is indicated as an entirety by A and the auxiliary air cleaneris indicatedl as an The casing of the air cleaner A is indicated by the numeral 1 and comprises a vertically disposed cylindrical section 2 that is closed at its top bya rigidly secured annular head 3 and at its bottom by 'a removable cap-like iuid receptacle orwell-4 that is filled with oil y to a normal lever marked y. The Huid receptacle 4 is telescoped over the lower end portion of the cylindrical casing section 2 to the extent permitted by pressed beads 5 and 5, respectively.

The casing 1 is provided wit-h an air inlet tube or conduit 6 that is extended axially thereinto through the annular head 3 thereof and terminates at its bottom considera-bly below the normal level y of oil in the receptacle or well 4. Near its top the casing section 2 is provided with a clean air outlet 7 that is adapted tobe connected to deliver to the intake of an internal combustion engine or the like in the conventional or any suitable manner. Interposed in the annular space between the inlet tube 6 and casing section 2 intermediate the iuid receptacle or well. 4 and the outlet 7 is a series of coni! cal dustintercepting 'oil spreading screens 8 and a filter 9 of suitable fibrous material, held against axial displacement by opposed upper and lower screens 10.

In practice, when air cleanersof the type described areused in connection withthe internal combustion engine of a tractor or other machine workin where dust, condi;

tions are extremely ba the intake tubes or .tube 6. is accomplished by means of a stand` pipe 6 that is telescoped into the upper end of the tube 6 on the upper end of which is 'mounted the Vcleaner 'B which subjects air to a primary cleaning before being delivered to the cleaner A. l The shell of the cleaner B is in the form of a truncated cone 11 closed at its contracted that is telescoped over the upper end of the stand pipe 6 and is provided therebetween and the shell 11' with a circumferentially spaced series ofdeflecting blades or vanes 14 that impart a whirling motion to air taken into the cleaner therebetween. The stand pipe, which affords an outlet for primarily cleaned air, is rojected considerably into the shell and may secured to the bottom plate 13 thereof b soldering or other suitable means; The s ell 11 is formed near the top of its contracted portion adjacent the head 12 with a dust discharge port 15. l

Under ,the action of suction in the stand pipe 6, air will be drawn into the shell`11 etween the blades 14, which blades will. impart a whirling motion thereto and dust .contained therein. The air will reverse its` direction of 'travel and pass outwardlyl through the stand pipe 6*. The whirling dust lupper end by a' head 12 and provided at itsI expanded lowerend with an annular plate 13` percentage of the dustV While the percentage of dust discharged upwardly projected stems 18 that work loosethrough the dust outlet 15 is very high, there will nevertheless be a considerable volume of dust remaining in the air which will be passed through stand pipe 6a therewith to the cleaner In this manner, most of the dust is separated from the air before delivery to the cleaner A, but some thereof, representing mostly vlight dust particles, will be passed withthe air outwardly through the stand pipe and under severe dust conditions, such as often encountered on plowed fields, this small percentage of dust will represent a considerale volume.

The air cleaner of my above identified application, likeother hitherto employed cleaners of the same general character, v,was provided with a non-expansible casing and frequently rendered considerable trouble as a result of backfiring of the engine with which it was employed through its intake. Such backliring of the engine through its intakel creates a sudden excessive pressure in the cleaner connected thereto intermediate its outlet and inlet and in the case of the cleaner of my said above identified application, wherein, as inthe present cleaner, the inlet extends normally into the body of oil,the force of the impact of the bac-kfired gases against the oil surrounding the inlet and the spontaneous rapid exhaust of the backlired gases through the body of oil into and through the 'intake shoots oil into and through the intake, thereby spreading an oil film over the inside surface thereof. In fact, when cleaners of this character having non-expansible casings are used in connection with a stand pipe and a primary air cleaner as here illustrated, vfor example, this up-shot or backfired oil will often pass far up into the said stand pipe and into the said primary cleanerand thereby coat the entire intake passage with a film of oil. Under continued operation of the engine, dust rapidly deposits upon the oiled surface of the intake tube, stand pipe and primary cleaner and soon forms a heavy coating which greatly restricts the intake and thereby renders the engine very inefficient.

In order to insure efficient operation of the engine after such backfiring it is necessary to clean out the entire intake passage which generally necessitates complete disassemblyof the air cleaning apparatus. It is the main object of -this invention to eliminate at least or reduce to a very great extent this undesired oiling of the intake passage when the engine backires-and to this end, I render the casing expansible under` excessive internal pressure.

In the preferred arrangement illustrated, the fluid receptacle 4 is yieldingly secured to the cylindrical casing section 2 by quickly releasable yielding fasteners in the form of spring retracted plungers 16. These'plungers 16 have hook-shaped lower ends 17 and ly through lugs 19 fast on the casing-'section 2. Placed on the projected upper ends of the stems k18 of the plungers are coil compression springs 20 that react against the said lugs 19 and shoulders afforded by washers 21 that are held against outward movement by cotter pins or the like 22. The free ends of the hooks 17 of the plungers 16 normally engage channel-like flanges 23 formed on the upper end of the fluid receptacle 4. The plungers, being normally retracted by the springs 20, yieldingly press the fluid receptacle 4 toward the casing section 2. The hooks 17 serve as finger-pieces and by means thereof the plungers may be pulled out of engagement and alignment with the channels 23 thereby permitting removal of the fluid receptacle.

When a backfire occurs, and a consequent excessive high pressure is built up in the cleaner surrounding the intake 6, the'springs 2O yield and permit outward expanding movements of the fluid receptacle 4 to the extent shown by dotted lines in the drawing, thereby absorbing much of the impact of backfired gases and lowering the oil to a level considerably below thev lower end of the intake. y With the impact thus partially absorbed and the oil lowered to a level below the intake tube, backiired gases will be discharged through the intake quite freely without greatly disturbing the body of oil. The amount' of oil shot into the intake is thus very greatly reduced.

It is here important to note that the springs 20 become fully compressed while the fluid receptacle is still in telescopic engagement` with the casing section 2 and therefore act as stops to limit expanding movements of the receptacle and accidental displacement thereof from the casing section 2. It will of course be obvious that after the cleaner has been relieved of excessive pressure caused by a backfire, the springs 20 will retract the plungers 16 and fluid receptacle 4 to their normal positions and render the vcleaner ready for continued operation.

To further aid in quickly relieving the cleaner A of excessive pressure resulting from backfire and thereby further decrease the amount of oil blown into the intake tube, a series of perforations 24 may be provided in the portion of the casing section 2 that is normally telescopically engaged by the fluid receptacle 4. These perforations 24 are normally closed by the surrounding portion of the fluid receptacle but are opened to the atmosphere under outward .movements of fluid receptacle and when open, some of the backfired gas will discharge therethrough and relieve the pressure with the casing.

What I claim is:

.1f In an air cleaner, the combination with a casing comprising a shell-like section having an opening in its lower end and inlet and outletpassages, a fluid reservoir normally frictionally engaging the open end portion of the casing and affording a closure therefor, of means for yieldingly pressing said vfluid reservoir toward said open end section but permitting outward movements thereof under excessive internal pressure. 2. In an air cleaner, the combination with a casing comprising a shell-like casing having an opening in its lower end and inlet and outlet passages, and a fluid reservoir normally frictionally engaging the said casing 3L section surrounding the opening in the bot- A tom thereof and affording a closure therefor, of yielding fasteners for detachably securing said fluid reservoir in an operative position and operative under excessive internal pres- 9 sure to yield and permit limited outward movements of said fluid receptacle.

3. In an air cleaner, the combination with a casing comprising a fixed and a relatively movable section, the latter section having 5 sliding telescopic engagement with the former and containing a body of liquid and the former being provided with an air outlet and an air inlet that is directed toward and terminated in close relation to the body of liquid, of readily detachable means normally yieldingly pressing the movable casing section toward the fixed casing section and being operative under impact caused by a sudden rise of internal pressure to yield and permit outward expanding movements of the movable section.

4. In an air cleaner, the combination with a casing comprising a fixed and a relatively movable section, the latter having sliding tel-4 escopic engagement with the former and containing a body of liquid and the former being provided with an air outlet, and an air inlet that terminates below the normal level of said body of liquid, of readily detachable y means normally yieldingly pressing the movable casing section toward the fixed casing section and operative under impact caused by a sudden rise of internal pressure to yield and permit limited outward movements of the movable casing section. 5. The structure defined in claim 3 in further combination with a perforation in the portion of one of said casing sections that is normally telescopically engaged by the other of said casing sections whereby said perforation will lnormally be closed but will be opened under outward movements of said movable casing section.

In testimony whereof I afix my signature.

WILFRED W. LOWTHER. 

